Caption: Mealy bugs on grape vine. Mealy bugs (Planococcus ficus) on the trunk of a grape vine (Vitis sp.). Female mealy bugs feed on plant sap, normally in roots or other crevices. They attach themselves to the plant and secrete a powdery wax layer used for protection while they suck the plant juices. The males on the other hand, are short-lived as they do not feed at all as adults and only live to fertilize the females. Small infestations of these bugs may not inflict significant damage to the grape vines, but in larger amounts they can induce leaf drop.